Field of the Invention
The invention relates to a method for training adjustment in sports, particularly a method for training adjustment in sports based on measuring lactate concentrations in the body of a person by a lactate measuring device.
Description of the Related Art
To generate muscle power, a human or other muscle primarily uses carbohydrates as a source of energy. There are two ways, aerobic metabolism and anaerobic metabolism, for carbohydrates to produce energy. As carbohydrates decomposed in anaerobic conditions, the carbohydrates will not only produce energy, but also produce lactate. When exercise intensity is low, muscle generates energy predominantly in the aerobic metabolism and only a small portion in anaerobic metabolism, thus the speed of the lactate production is not high and can be metabolized easily by the human body, so the lactate does not accumulate in the human body and blood. The greater the exercise intensity, the greater the use of the anaerobic metabolism and the higher the speed of the lactate production. The speed of the lactate elimination cannot catch up the speed of the lactate production, and thus the lactate started to accumulate in the human body. At the exercise intensity, the lactate level in the human body between aerobic metabolism and anaerobic metabolism is referred to “lactate threshold.” At the lactate threshold between aerobic metabolism and anaerobic metabolism, the lactate level in the human body remains in balance. If the lactate threshold and the associated heart rate of an athlete are known, the athlete can optimize his training according to this.
Lactate is the most important biomarkers in organism oxygenation, and thus the lactate is extremely important in the application of sport and health care. The lactate concentration provides information on anaerobic threshold. This information is very important to develop endurance sports training program. Currently, the development of lactate measuring devices is driven from the commercial interests in sports, fitness, dairy and defence industries.
The normal blood lactate concentration of a human is in the range of 0.5-2 mM in a static resting. However, when a human does a strenuous exercise with the metabolism in the muscle passing into the anaerobic threshold or a human is injured to trigger a hemorrhagic shock, oxygen supplied by cells becomes limited and lactate will increase rapidly. Lactate measurement can help identify the fatigue reaction of athletes and sports lovers and particularly important for soldiers and provides a personalized training process for athletes. Lactate measurement is connected with clinical significance of many intensive care cases, for example, lactateosis, especially in a state of shock.
There are some exercise physiologists proposed the change of blood lactate during exercise and after exercise is in relation to the balance among lactate generation rate of skeletal muscles, the rate of lactate entering the blood and the metabolism rate of lactate in the blood. The blood lactate concentration relates to exercise intensity, lasting time and the metabolism function of tissues and organs. During exercise and after exercise, the physiologic data and the influence of the human body can be obtained by continuously determining blood lactate value. Determination of blood lactate value can be used in training adjustment in sports. In order to provide a perfect training course and plan, a coach has to figure out optimum exercise intensity and demand for an athlete. It was reported in exercise physiological journals that blood lactate value in resting is about 1.0 mM used as a judge basis to exercise intensity, and blood lactate value is about 4.0 mM used as a judge basis to the threshold of the anaerobic metabolism. Another exercise physiological journal disclosed that the blood lactate value may reach about 30 μM/g when a human does a strenuous exercise, and the muscle stressed and hardly to perform exercise when lactate value reaches to 20-25 μM/g in the muscle.
There is an exercise physiological journal disclosed that lactate production in sport is mainly connected with the intensity of exercise loading, portion of muscle involved to exercise and the time during exercise. In addition, lactate concentration is connected with the percentages of aerobic metabolism and anaerobic metabolism in sport. To generate muscle power, a human or other muscle requires energy that must be supplied by the organism. There are three types of energy supply system including phosphagen system, glycolytic system and aerobic system. As energy is supplied by the phosphagen system, blood lactate concentration is low, typically less than 4 mM. As energy is supplied by the glycolytic system, blood lactate concentration may reach to 15 mM. As energy is supplied by the aerobic system, blood lactate concentration is about 4 mM. The change of blood lactate during exercise depends on the energy supply system. Therefore, the accumulation of blood lactate is obviously different with the training intensity. The accumulation of blood lactate has two meanings: one is to generate a lot of energy providing for muscle contraction, for the glycolytic function is accelerated. Another means that acidic level in the muscle is increased, and the energy is supplied predominantly by the anaerobic glycolytic function as a result of the function of aerobic metabolism is not enough. There are some exercise physiologists proposed that the accumulation of blood lactate can be used as a physiological parameter for determining exercise loading of athletes in a stable condition.
The common cause of the accumulation of blood lactate is oxygen deficiency. The lactate concentration is conventionally determined with a lactate test strip which effects a blood analysis of blood samples that are extracted from the athlete at different stresses outside of the laboratory. However, the result has less help for predicting the dynamic change of lactate concentration and establishing a precise concentration again. In fact, the blood sampling is inconvenient when the exercise is implemented. The result cannot be explained directly.
It is not a practical method to directly implant a lactate measurement device in blood vessel that is connected with a risk of thrombus, and causes the interaction between the lactate measurement device and blood flowing through thereof to result in kinetic change of the blood flowing through the lactate measurement device. In contrast, a transdermal sensor is safe by measuring lactate concentration in tissue fluid. Also, the lactate concentration of tissue fluid can provide more information about local oxygen supply. Therefore, the oxygen deficiency of a portion of tissue can be measured without obtaining average value from the blood analysis.
The lactate value is conventionally determined with a lactate measurement device which effects a blood analysis of blood samples that are extracted from the athlete at different stresses. The known solution is, disadvantageously, an invasive method, especially since blood samples must be extracted from the test person (e.g., an athlete) to be tested. This is, on the one hand, sometimes painful for the athlete. On the other hand, the blood extraction is always connected with a risk of infection, for example, with hepatitis or HIV, for both the test person and for the examiner. To reduce this infection risk, high hygiene standards are in turn necessary that make the method elaborate and expensive.
In addition, a conventional non-invasive method to determine the LBP, designated as a “Conconi test”, is increasingly being used in sports medicine. In this method, a test person runs on a 400 m athletic track for a length of 200 m with a predetermined speed, for example 8 km/h. After respectively 200 m, the test person increases the tempo in stages, for example, by respectively 0.5 km/h. At each 200 m mark of the athletic track, the test person notes his current heart rate and calls it out to an attendant after respectively circling the athletic track. The test person runs on the track until he has reached a power limit, meaning he cannot further increase the speed.
For test evaluation, the heart rate is plotted against the associated running speed in a two-dimensional (X-Y) diagram. A characteristic finding hereby results: in the aerobic range, given a comparably low power, the heart rate runs nearly linearly with the running speed. This means that the heart rate increases in the same proportion as the power generated by the test person. This regularity is broken at the threshold to the anaerobic metabolism. In the anaerobic high-power range, the heart rate increases comparatively only slightly with further-increasing power or, respectively, running speed. The function of the heart rate dependent on the running speed thus shows a clear, more or less sharp break at the transition from the aerobic low-power range to the anaerobic high-power range, via which the LBP is determined. The heart rate characteristic for the LBP and the associated running speed can be simply read from the X/Y diagram.
However, the Conconi test is comparably elaborate and can hardly be executed without a trained attendant. Additionally, with the Conconi test the LBP can be determined only comparatively imprecisely, due to the weather dependency and the capability of the test person to precisely control his speed.
In summary, there is a need to provide a low invasive lactate measuring device for transdermal continuously monitoring the lactate concentration in the human body. The lactate measuring device is suitable in sports, working out and military training, particularly athletes and sports lovers to avoid muscle acidic and painful.